The objectives of this Core are: to maintain a resource laboratory for measuring eicosanoid concentrations in biologic fluids; to share costly resources required for studying the biochemistry of the cyclooxygenase and lipoxygenase metabolites of arachidonic acid; and to provide consultation to SCOR investigators regarding suitable methods and experimental designs for the collection and measurement of these compounds. Using equilibrium radioimmunoassay techniques, the laboratory will measure prostaglandins (PGE2, PGF2alpha, PGD2, and the stable hydrolysis products of PGI2 (6-Keto-PGF1 alpha) and thromboxane A2 (Thromboxane B2, TxB2), 12 and 5 hydroxyeicosatetraenoic acid (12 and 5 HETE), and the leukotrienes B4 (LTB4) and C4 (LTC4) in lung washings and cell culture fluids.